Lp 1899974: Export PERL5LIB in oils_ctl.sh

Lp 1899974: Export PERL5LIB in oils_ctl.sh

A change in Perl release 5.26.0 necessitates that the SIP_DIR variable
(default value "/opt/SIPServer") be exported to the environment in
oils_ctl.sh when attempting to start SIPServer.  This change affects
Ubuntu 18.04 (Bionic Beaver) and Debian 10 (Buster) and any future
releases.

To verify the bug:

1. Install OpenSRF, Evergreen, and SIPServer on an affected O/S.
2. Start OpenSRF service.
3. Start SIPServer via oils_ctl.sh:
   oils_ctl.sh -a start_sip
4. Notice the "Starting OILS SIP Server" message is printed with no
   indication of failure.
5. Verify that the PID file exists: /openils/var/run/oils_sip.pid
6. Verify that no SIPServer processes are actually running:
   pgrep -af SIPServer
   The above should produce no output.

To test this patch:

1. Apply this patch and install oils_ctl.sh to /openils/bin/.
2. Assuming you have run the previous steps, delete the PID file:
   rm /openils/var/run/oils_sip.pid
3. Start SIPServer via oils_ctl.sh:
   oils_ctl.sh -a start_sip
4. Notice the "Starting OILS SIP Server" message is printed.
5. Verify that the PID file exists: /openils/var/run/oils_sip.pid
6. `pgrep -af SIPServer` should produce output.

It is safe to apply this patch on an unaffected O/S.  Explicitly
adding SIP_DIR to PERL5LIB will have no detrimental effect on any O/S
currently supported by Evergreen.

Signed-off-by: Jason Stephenson <jason@sigio.com>